perimeter of the triangle is $${\frac{{\mathtt{403}}}{{\mathtt{60}}}}$$ cm determine the length of the unknown side
s1=$${\frac{{\mathtt{18}}}{{\mathtt{5}}}}$$cm
s2=$${\frac{{\mathtt{8}}}{{\mathtt{3}}}}$$ cm
s3=?
s3 = 403/60 - 18/5 - 8/3
s3 = 403/60 - 216/60 - 160/60 = 27/60 = 9/20
